Improve your toilet’s water efficiency


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Water-efficient toilets do the same job as inefficient ones but use much less water. Older model toilets can use up to 12 litres of water per flush, whereas dual-flush toilets use only 3 litres on a half-flush.


Toilet with a hand basin

Toilet with a hand basin

New toilets must have a Water Efficiency Labelling and Standards (WELS) scheme star rating to show how water-efficient they are. The more stars the more water efficient. Aim for a toilet with a minimum 3-star rating. There are also 5-star models that re-use water from a hand washing basin. The hand basin sits on top of the cistern and the water you wash your hands with is then used to flush your toilet.


Toilet Water Saver device

Toilet Water Saver

Single flush toilets can be made more efficient by:

  • adjusting the float valve in the cistern to reduce the amount of water needed to fill the cistern for each flush
  • installing a Toilet Water Saver. It simply fits into the open overflow causing the toilet to only flush whilet the flush button or lever is held down
  • inserting a water displacement device in your cistern. You can purchase one or place a plastic bottle filled with water in the cistern. Don't use bricks as they can crumble and stop the system working properly
  • having a plumber adjust the flush volume of your cistern


Leaking toilet

Leaking toilet

A leaking toilet can waste over 16,000 litres of water a year. You can check if your toilet is leaking (and then fix it of course):

  • Place a small piece of dry toilet paper at the back of the toilet bowl and check that it stays dry until the next flush. Toilet cisterns shouldn't release any water between flushes
  • Place a couple of drops of food colouring or dye into the cistern. If colour appears in the bowl within 15 minutes without flushing, there's a leak
Last Updated: 
Fri 18/03/2016

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